Piston pneumatic actuator

Abstract

This utility model discloses a piston-type pneumatic actuator, including a drive housing and a cylinder housing. The cylinder housing is located on one side of the drive housing, and a drive chamber is provided inside the drive housing. A pressure plate is provided inside the cylinder housing, and an air chamber is provided on one side of the pressure plate. An output shaft is provided on the other side of the pressure plate. The output shaft passes through the cylinder housing and extends into the drive chamber for reciprocating movement. A valve stem is rotatably mounted inside the drive housing, and one end of the valve stem extends into the drive chamber and is connected to a connecting rod. A strip-shaped groove is provided on the connecting rod. A drive block is fixedly connected to the portion of the output shaft located in the drive chamber. A slide rod is provided on the drive block, and the slide rod slides in the strip-shaped groove. The output shaft drives the connecting rod and the valve stem to reciprocate and rotate reciprocally through reciprocating movement. This solution converts linear motion into the reciprocating rotational motion of the valve stem, thereby realizing the opening and closing control of the valve, and has the advantages of smooth movement and fast response.

Description

Technical Field

[0001] This utility model belongs to the field of actuator technology, specifically relating to a piston-type pneumatic actuator. Background Technology

[0002] Pneumatic actuators are a type of actuator commonly used in automatic control systems, and are widely used in valve driving, fixture control, automatic assembly, and other applications. In the current technology, most common pneumatic actuators adopt a linear structure, which directly drives the output shaft to perform telescopic motion through the reciprocating movement of the piston, thereby pushing or pulling the valve stem and completing the opening and closing control of the valve.

[0003] Chinese patent application number 2021210634526 discloses a piston-type pneumatic actuator, including a bracket and a cylinder assembly. The cylinder assembly includes a cylinder, a piston, a piston rod, and an elastic element. The cylinder is connected to one end of the bracket. The piston is slidably disposed within the cylinder. One end of the piston rod is connected to the piston, and the other end slides out of the cylinder and extends into the bracket. One end of the elastic element is connected to the inner wall of one end of the cylinder, and the other end is connected to the piston. The elastic element pushes the piston to move to the inner wall of the other end of the cylinder. The cylinder has an air port communicating with the inside of the cylinder. Gas is injected into the cylinder through the air port to push the piston to compress the elastic element. This design has the advantages of long service life and the ability to withstand higher control air pressure.

[0004] However, traditional telescopic control methods have certain limitations in practical use: on the one hand, frequent axial linear extension and retraction can easily lead to wear and leakage of valve stem seals, affecting the sealing performance and service life of the system; on the other hand, this type of structure cannot meet complex action requirements in some situations that require angle adjustment or rotational output, limiting its adaptability in multi-functional actuators. Utility Model Content

[0005] To solve the above problems, this utility model provides a piston-type pneumatic actuator, including a drive housing and a cylinder housing. The cylinder housing is located on one side of the drive housing, and the drive housing has a drive cavity inside. The cylinder housing has a pressure plate inside, and one side of the pressure plate has an air chamber. The other side of the pressure plate has an output shaft. The output shaft passes through the cylinder housing and extends into the drive cavity for reciprocating movement. A valve stem is rotatably mounted inside the drive housing. One end of the valve stem extends into the drive cavity and is connected to a connecting rod. A strip-shaped groove is formed on the connecting rod. The portion of the output shaft located in the drive cavity is fixedly connected to a drive block. A slide rod is mounted on the drive block and slides in the strip-shaped groove. The output shaft drives the connecting rod and the valve stem to rotate reciprocally through reciprocating movement.

[0006] Preferably, a compression housing is provided on the side of the drive housing away from the cylinder housing, a piston chamber is provided inside the compression housing, a piston is provided in the piston chamber, one end of the output shaft extends into the piston chamber and is connected to the piston, and a connecting pipe is connected to the side of the piston chamber away from the drive chamber, and the connecting pipe is connected to the drive chamber.

[0007] Preferably, it also includes a heating pipe, one side of which is connected to a heat pump, and the other side of which is connected to a drive chamber.

[0008] Preferably, a return spring is provided on the side of the pressure plate away from the air chamber, and the side of the return spring away from the pressure plate is connected to the inner wall of the cylinder housing.

[0009] Preferably, a temperature sensor is provided inside the drive cavity.

[0010] The advantages of this utility model are: 1. This solution achieves the conversion from reciprocating linear motion of the piston to rotary motion of the valve stem through a linkage mechanism between the output shaft, drive block, slide rod, connecting rod, and valve stem. This conversion structure is compact and has a clear force distribution, avoiding the jamming or uneven wear problems caused by lateral forces in traditional telescopic valve stem structures, thereby improving transmission efficiency and response speed.

[0011] 2. This solution innovatively sets an auxiliary piston structure at the end of the output shaft, which compresses the air and generates heat during the reciprocating process, effectively heating the lubricating oil and the air in the cavity, preventing the lubricating oil from solidifying or its viscosity from increasing due to low temperature, and ensuring the normal start-up and operation of the pneumatic actuator in cold environments.

[0012] 3. This solution provides an additional auxiliary heat source by setting up a heat pump and heating pipes, and combines this with a temperature sensor to monitor the drive cavity temperature in real time, thus constructing a closed-loop temperature control mechanism. When the system detects a low temperature, the heat pump can automatically start and stop to replenish heat, effectively avoiding a decline in lubricating oil performance or an increase in transmission resistance, and significantly improving the reliability and lifespan of the equipment in extreme temperature ranges. Attached Figure Description

[0013] Figure 1 This is a diagram of the overall external structure of this utility model.

[0014] Figure 2 This is a three-dimensional sectional view of the present invention.

[0015] Figure 3 This is a planar sectional view of the present invention.

[0016] In the diagram: 1 Drive housing, 2 Cylinder housing, 3 Drive chamber, 4 Pressure plate, 5 Air chamber, 6 Output shaft, 7 Valve stem, 8 Connecting rod, 9 Strip groove, 10 Drive block, 11 Slide rod, 12 Compression housing, 13 Piston chamber, 14 Piston, 15 Connecting pipe, 16 Heating pipe, 17 Return spring, 18 Temperature sensor. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0018] In the description of this utility model, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0019] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," and "connected," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Simultaneously, when an component is referred to as "fixed to" or "equipped on" another component, it can be directly on the other component or may have an intervening component present. When an component is referred to as "connected to" another component, it can be directly connected to the other component or may have an intervening component present. When an component is referred to as "fixedly connected to" another component, it can be a common fixed connection method such as welding, bolting, or gluing. In short, those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0020] Example 1, as Figure 1-3 As shown, a piston-type pneumatic actuator includes a drive housing 1 and a cylinder housing 2. The cylinder housing 2 is located on one side of the drive housing 1, and the drive housing 1 has a drive chamber 3 inside. The cylinder housing 2 has a reciprocating pressure plate 4 inside, and a compressed air chamber 5 is provided on one side of the pressure plate 4 for inputting compressed air. The compressed air chamber 5 is intermittently pressurized or vented by an air source, thereby driving the pressure plate 4 to perform reciprocating linear motion.

[0021] An output shaft 6 is connected to the other side of the pressure plate 4. The output shaft 6 passes through the cylinder housing 2 and extends into the drive cavity 3 inside the drive housing 1, and is used to transmit the linear reciprocating motion of the pressure plate 4 to the drive mechanism. One end of the output shaft 6 located in the drive cavity 3 is fixedly connected to a drive block 10. A slide rod 11 is provided on the drive block 10. The slide rod 11 extends laterally and is slidably disposed in the strip groove 9 of a connecting rod 8. The other end of the connecting rod 8 is connected to a rotatable valve stem 7. The valve stem 7 is axially arranged inside the drive housing 1 and can swing at an angle around its own axis.

[0022] When the output shaft 6 reciprocates linearly under pneumatic action, the drive block 10 drives the slide rod 11 to slide within the strip groove 9, thereby pushing the connecting rod 8 to drive the valve stem 7 to reciprocate in a swing manner. Through this structural design, the linear motion of the piston 14 is reliably converted into the angular rotational motion of the valve stem 7.

[0023] A compression housing 12 is provided on the side of the drive housing 1 away from the cylinder housing 2. The compression housing 12 is provided with a piston chamber 13 for thermal energy auxiliary function. A reciprocating piston 14 is provided in the piston chamber 13. One end of the output shaft 6 extends into the piston chamber 13 and is fixedly connected to the piston 14, so that the output shaft 6 can synchronously drive the piston 14 to move in the piston chamber 13 during each reciprocating motion.

[0024] A connecting pipe 15 is connected to the side of the piston chamber 13 away from the drive chamber 3. The connecting pipe 15 is connected to the drive chamber 3, and the piston 14 generates heat during the compression of air. When the output shaft 6 reciprocates under the push of the pressure plate 4, the piston 14 moves synchronously within the piston chamber 13, thereby compressing the air inside the chamber. The heat generated during compression heats the air inside the chamber and is introduced into the drive chamber 3 through the connecting pipe 15. To prevent the air from not being sealed during compression and flowing immediately into the drive chamber, resulting in a slight temperature rise, a one-way valve is installed on the air supply pipe. Only when the pressure inside the compression chamber reaches a certain threshold can the valve opening pressure be overcome to push the gas out, so that the air inside the compression chamber is completely compressed and the air temperature rises further. The inner wall of the piston chamber is also coated with an insulating or reflective coating, such as a ceramic coating, to reduce heat loss and improve compression efficiency.

[0025] The output shaft 6 drives the auxiliary piston 14 to perform compression motion in the closed cavity. The heat energy generated during the compression of air by the piston 14 is effectively utilized to heat the air and lubricating oil in the drive cavity 3, avoiding the solidification or viscosity increase of the lubricating oil due to the low temperature environment, which would affect the response speed and working reliability of the actuator.

[0026] To further enhance operational reliability in low-temperature environments, the drive housing 1 is equipped with a heating pipe 16. One end of the heating pipe 16 is connected to a heat pump device, and the other end is connected to the drive cavity 3. The heat pump heats the air inside the heating pipe 16 and transfers the heat to the drive cavity 3, thereby providing continuous temperature-controlled heating for the air and lubricating oil inside the drive cavity 3. The heat pump heating system, as an auxiliary heat source, works in conjunction with the piston 14 compression heating structure to further ensure that the drive cavity 3 remains within a suitable operating temperature range. Even in extremely cold environments, it effectively prevents the lubricating oil from solidifying, increasing in viscosity, or decreasing in fluidity due to excessively low temperatures, thus enhancing the actuator's low-temperature start-up performance and long-term stable operation capability. A temperature sensor 18 is installed inside the drive cavity 3. The temperature sensor 18 monitors the temperature changes of the lubricating oil and the air inside the cavity. The signal from the temperature sensor 18 serves as the basis for controlling the start and stop of the heat pump or compression heating module, achieving intelligent temperature control and preventing lubricating oil solidification due to excessively low temperatures or deterioration of lubricating oil performance due to excessively high temperatures, thereby effectively extending the equipment's service life.

[0027] A return spring 17 is provided on the side of the pressure plate 4 away from the air chamber 5. The side of the return spring 17 away from the pressure plate 4 is connected to the inner wall of the cylinder housing 2. The return spring 17 provides stable mechanical elasticity, which can ensure reliable reset even under low air pressure or light load conditions, thereby improving the overall action consistency and response stability of the pneumatic actuator.

[0028] During operation, air is supplied to the air chamber 5 located inside the cylinder housing 2 via an air source. The output shaft 6 passes through the cylinder housing 2 and extends into the drive chamber 3. As the output shaft 6 reciprocates linearly, the slide rod 11 slides in the slide groove, pushing the connecting rod 8 to swing around one end of the rotational connection point, thereby driving the valve stem 7 connected to the connecting rod 8 to reciprocate around its own axis. Through this mechanism, linear motion is effectively converted into angular rotational motion of the valve stem 7, thereby realizing rotational control of valves and other controlled devices.

[0029] Simultaneously, during its movement, the output shaft 6 also drives the auxiliary piston 14, located inside the compression housing 12, to reciprocate within the piston chamber 13. This auxiliary piston 14 compresses the air within the piston chamber 13, increasing its temperature and generating heat. This heat effectively prevents the lubricating oil from solidifying or increasing in viscosity due to low temperatures, ensuring good lubrication of the transmission structure within the drive chamber 3 and improving the actuator's response speed and reliability. Furthermore, a heat pump and a connected heating pipe 16 are installed outside the drive housing 1. The heat pump provides further heat compensation to the drive chamber 3 based on the working environment or system feedback temperature signals, especially in extremely cold environments, continuously maintaining the drive chamber 3 within a suitable temperature range. A temperature sensor 18 is installed inside the drive chamber 3, which monitors internal temperature changes in real time and feeds the temperature signal back to the control system to control the start and stop of the heat pump or compression heating system, achieving intelligent temperature control and ensuring that the lubricating oil's performance is not affected by excessively high or low temperatures. In addition, a return spring 17 is provided on the side of the pressure plate 4 away from the air chamber 5, and one end of the return spring 17 is fixed to the inner wall of the cylinder housing 2. In the event that the air supply stops or the pressure drops, the return spring 17 can provide reliable elastic force to automatically reset the pressure plate 4 and the output shaft 6, thereby restoring the actuator to the initial position and preventing the actuator from staying in the intermediate state due to the interruption of air supply, effectively improving the system safety and operational reliability.

[0030] Through the above process, this pneumatic actuator not only achieves efficient conversion from linear motion to rotary motion, but also has good low-temperature resistance, self-resetting function and intelligent thermal control mechanism, making it particularly suitable for stable operation in cold or complex industrial environments.

[0031] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A piston-type pneumatic actuator, characterized in that: The device includes a drive housing (1) and a cylinder housing (2). The cylinder housing (2) is located on one side of the drive housing (1). The drive housing (1) has a drive cavity (3) inside. The cylinder housing (2) has a pressure plate (4) inside. One side of the pressure plate (4) has an air chamber (5), and the other side of the pressure plate (4) has an output shaft (6). The output shaft (6) extends through the cylinder housing (2) into the drive cavity (3) for reciprocating movement. The internal rotating part is provided with a valve stem (7), one end of which extends into the drive cavity (3) and is connected to a connecting rod (8). A strip groove (9) is provided on the connecting rod (8). The part of the output shaft (6) located in the drive cavity (3) is fixedly connected to a drive block (10). A slide rod (11) is provided on the drive block (10). The slide rod (11) is slidably disposed in the strip groove (9). The output shaft (6) drives the connecting rod (8) and the valve stem (7) to rotate back and forth by reciprocating movement.

2. The piston-type pneumatic actuator according to claim 1, characterized in that: The drive housing (1) has a compression housing (12) on the side away from the cylinder housing (2). The compression housing (12) has a piston chamber (13) inside. The piston chamber (13) has a piston (14) inside. One end of the output shaft (6) extends into the piston chamber (13) and is connected to the piston (14). A connecting pipe (15) is connected to the side of the piston chamber (13) away from the drive chamber (3). The connecting pipe (15) is connected to the drive chamber (3).

3. The piston-type pneumatic actuator according to claim 2, characterized in that: It also includes a heating pipe (16), one side of which is connected to a heat pump, and the other side of which is connected to the drive chamber (3).

4. The piston-type pneumatic actuator according to claim 3, characterized in that: A return spring (17) is provided on the side of the pressure plate (4) away from the air chamber (5), and the side of the return spring (17) away from the pressure plate (4) is connected to the inner wall of the cylinder housing (2).

5. The piston-type pneumatic actuator according to claim 4, characterized in that: A temperature sensor (18) is provided inside the drive cavity (3).

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